Celestia Forums

I'm sure everyone here knows moons will, in a mature system, tend to be tidally locked for reasons of, well, tidal forces. My question is for immature systems, younger ones. Are there any equations out there, or better yet some sort of online calculator, that can simulate moon systems and give reasonable estimates as to what their rotations would be like at a given age? The star system that got me thinking about this is Epsilon Indi, which is about 1.3 gigayears old, I was making moons for my fictional worlds there and stopped to think, would they neccessarily be tidally locked yet?

1.3 billion years is still a long time for tidal locking to take place. The issue that is brought up in the forums would only exist for systems that are extremely young, such as Beta Pictoris (about 8 million years old). As an example, some tidal lock times :

Moon tidally locked to Earth...............< 7 million years
Callisto tidally locked to Jupiter...........66,000 years
Iapetus tidally locked to Saturn............556 million years
Oberon tidally locked to Uranus............400,000 years
Dysnomia tidally locked to Eris.............66 million years

What this shows is that tidal locking, especially when planet-sized moons or moons very close to the primary, are involved, will happen very quickly.

Moon tidally locked to Earth...............< 7 million years
Callisto tidally locked to Jupiter...........66,000 years
Iapetus tidally locked to Saturn............556 million years
Oberon tidally locked to Uranus............400,000 years
Dysnomia tidally locked to Eris.............66 million years

Ah, as I suspected, the equation I found approximating planetary locking to stars does not scale down well at all. This is good to know, thank you.